A dirty paper precoding (“DPC”) method for broadcasting a signal is disclosed that takes advantage of knowledge of the structure of interference in order to avoid the quantization noise that results in the conventional DPC method. The proposed method modifies the Tomlinson-Harishima precoding (“THP”) scheme by selecting a constellation and mapping scheme that is designed based on the known interference modulation structure of the interference signal, which is typically directed to a second receiver. In a particular embodiment, a source signal and an interference signal are QAM modulated. The modulation structure information of the interference signal is known to the receiver. At the transmitter the source signal is precoded based on the known interference structure, and a common mapping rule is implemented, such that the received signal can be decoded at the receiver without requiring a modulo operation at either the transmitter or receiver.